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[Systolic time intervals and abnormal left ventricular contraction in coronary heart disease (author's transl)]
Insights
Systolic time intervals (STI) reflect left ventricular (LV) function in chronic coronary heart disease (CHD). Abnormal STIs correlate with reduced LV contraction and increased pulmonary pressure, aiding in patient classification.
Area of Science:
- Cardiology
- Cardiovascular Physiology
Background:
- Chronic coronary heart disease (CHD) affects left ventricular (LV) function.
- Systolic time intervals (STI) offer non-invasive insights into cardiac mechanics.
Purpose of the Study:
- To correlate systolic time intervals (STI) with hemodynamic and angiographic data in patients with chronic coronary heart disease (CHD).
- To assess the relationship between STI abnormalities and the extent of LV contraction abnormalities and pulmonary pressures.
Main Methods:
- Investigated 72 patients with chronic CHD undergoing cardiac catheterization.
- Measured hemodynamic parameters, performed LV and coronary angiography.
- Recorded non-invasive phonocardiograms, apexcardiograms, and carotid pulses to calculate STI (QA2, LVET, PEP, IVCT, IVRP, PEP/LVET ratio).
Main Results:
- Prolonged pre-ejection period (PEP) and isovolumetric contraction time (IVCT) correlated with reduced LV contraction (r=0.816).
- Shortened left ventricular ejection time (LVET) and electromechanical systole (QA2) increased with the severity of LV dysfunction.
- The PEP/LVET ratio significantly increased with LV dyskinesis and aneurysm, correlating with elevated pulmonary pressures.
Conclusions:
- Systolic time intervals (STI) are significantly altered in chronic CHD patients with impaired LV contraction.
- Non-invasive STI can help classify patients based on the degree of LV contraction abnormality.
- While STI provides valuable classification, precise estimation of LV and pulmonary pressures requires invasive measurements.
Unlabelled:
Systolic time intervals (STI) were determined in relation to haemodynamic and angiographic data in 72 patients (pts.) with chronic cornary heart disease (CHD). Routine right-and left-heart catheterization was performed with a view to coronary surgery and/or left ventricular (LV) aneurysmectomy. LV and pulmonary pressure were measured before LV and coronary angiography. Non-invasive investigation (not simultaneously done with catheterization) included the registration of phono-and apexcardiogram and the carotid pulse. The following time intervals were averaged over a period of 5 beats: electromechanical systole (QA2), left ventricular ejection time (LVET), pre-ejection period (PEP), electro-mechanical interval (EMI), isovolumetric contraction and relaxation period (IVCT and IVRP), and the ratio PEP/LVET. LV angiography showed normal con-raction in 24 pts., localized dyskinesis in 25 pts., aneurysm in 12 and generalized dyskinesis in another 11 pts. (groups 1-4).
Results:
in pts. with chronic CHD, PEP and IVCT are prortionally prolonged (r=0.816***). QA2 and (even more) LVET are shortened. The correlation of LVET and QA2 with heart rate remains significant (p less than 0.005). Prolongation of PEP and IVCT and shortening of LVET and AQ2 increase with the extent of LV contraction abnormality. The degree of STI abnormality correlates with an increase in pulmonary pressure. Shortening of LVET does not correlate with lengthening of PEP. PEP/LVET ratio increases significantly with LV dyskinesis: being 0.394+/-0.085 in pts. with normal contraction, 0.448+/-0.076 with normal contraction, 0.448+/-0.076 with localized dyskinesis, 0.541+/-0.167 with generalized dyskinesis and 0.565+/-0.093 with LV aneurysm. -IVRP is prolonged (to 0.131+/-0.019 sec) without significant differences between the four groups. Non-invasive findings in chronic CHD roughly classify pts. into groups with definite LV contraction abnormality. However, clear estimation of the actual pressure in the (diastolic) LV and in the pulmonary circulation from non-invasive data is of course not possible.